1. Field of the Invention
This invention relates to hierarchical pyramid signal processing techniques for analyzing the frequency spectrum of an information component (having one or more dimensions) of a given temporal sampled signal having a highest frequency of interest no greater than f.sub.0, and/or for synthesizing such a temporal signal from the analyzed frequency spectrum thereof. This technique may be implemented in delayed real time by apparatus employing pipe-line architecture of a type disclosed in the aforesaid co-pending Carlson et al. application. Although not limited thereto, the present invention is particularly suitable for image-processing in delayed real time the two-dimensional spatial frequencies of television images defined by a temporal video signal.
2. Description of the Prior Art
Prior to the present invention, Dr. Peter J. Burt developed an algorithm (hereinafter referred to as the "Burt Pyramid"), which he utilized to both analyze the spatial frequency spectrum of images and to synthesize an image from its analyzed sub-spectra. The Burt Pyramid algorithm (which uses particular sampling techniques discussed in some detail in the aforesaid co-pending Carlson et al. application) permits an original high-resolution image to be synthesized from component sub-spectra images without the introduction of spurious spatial frequencies due to aliasing. Originally, the Burt Pyramid algorithm was implemented by computer in non-real time. Non-real time implementation of the Burt Pyramid algorithm by computer processing is effective in processing fixed image information. However, it is not applicable to a stream of successively-occurring images which can be continually changing in time (e.g., successive video frames of a television picture). The generic invention which forms the subject matter of the aforesaid co-pending Carlson et al. application permits a real time implementation of both an analyzer and a synthesizer in accordance with the Burt Pyramid algorithm, as well as the real time implementation of just the analyzer of a filter-subtract-decimate (FSD) hierarchical pyramid which forms part of the subject matter of the present invention.